Band 34, Heft 10

(CH 3 ) 3 Pconvertsa,a,w-dibromopentaneand-hexane into w-bromoalkyltrimethylphos-phonium bromides,which undergo a cyclizationon treatment with NaNH 2 in tetrahydro-furane to form the cyclopentyl-and cyclohexyl-dimethyl-methylenephosphoranes 4 and 5. From the bis-phosphonium salt(CH 3 ) 3 P(CH 2 ) 6 P(CH 3 ) 3 2⊕ 2Br ⊖ the difunctional bis-ylide CH 2 =(CH 3 ) 2 P(CH 2 ) 6 P(CH 3 ) 2 =CH 2 (7)is obtained. The ylide 4 was characterized by the crystalline metallocyclic Au(I)derivative 8.7 forms a polymeric gold complex.

N,N,N′-Tris- and N,N,N′,N′-tetrakis(1,3-dimethyl-1,3,2-diazaborolidinyl)hydrazine (4)were prepared via N,N′-lithiated N,N′-bis(1,3-dimethyl-1,3,2-diazaborolidinyl)hydrazine. 4 crystallizes monoclinic.The N-N axes of the 4 molecules coincide with the crystallo-graphic twofold axes. Its N-N bond is rather long(146.4qm and the ring BN bonds are shorter than the BN bond to the hydrazine nitrogen atoms. This indicates preferential electronic saturation of the boron atoms via ring BN II bonding.

(R 3 P) 2 NiCl 2 and LiP(SiMe 3 ) 2 react in a complex reaction sequence finally yielding (R 3 P) 2 Ni(PSiMe 3 ) 2 (5), containing a three-membered PNiP ring system, and [R 3 PNiP(SiMe 3 ) 2 ] 2 (6), containing a (PNi) 2 four-membered ring system with a nickel-nickel bond, respectively. NMR data are reported.

[CO(CO) 2 (R 2 PCH 2 ) 3 CCH 2 PR 2 ][CO(CO) 4 ] (R = C 6 H 5 ) was synthesized in a simple manner from Co 2 (CO) 8 and the tetratertiary phosphine C[CH 2 P(C 6 H 5 ) 2 ] 4 , which acts only as a tridentate ligand. [Co(CO) 2 (R 2 PCH 2 ) 3 CCH2PR2][Co(CO) 4 ] reacts with NH 4 PF 6 , NaBH 4 , NaBD 4 or liquid ammonia at 20 °C to [Co(CO) 2 (R 2 PCH 2 ) 3 CCH 2 PR 2 ]PF 6 , CoH(CO) 2 (R 2 PCH 2 ) 2 C(CH 2 PR 2 · BH 3 ) 2 , CoD(CO) 2 (R 2 PCH 2 ) 2 C(CH 2 PR 2 · BD 3 ) 2 or Co(CO)(CONH 2 )(R 2 PCH 2 ) 3 CCH 2 PR 2 . In liquid ammonia [Co(CO) 2 (R 2 PCH 2 ) 3 CCH 2 PR 2 ][Co(CO) 4 ] at 60 °C yields the hydride CoH(CO)(R 2 PCH 2 ) 3 CCH 2 PR 2 . The new compounds were characterized, as much as possible, by their IR, Raman and 1 H NMR data.

Anhydrous chromium(III) chloride reacts with pure carboxylic acids (RCOOH where R = CH 3 , C 2 H 5 , n-C 3 H 7 , CH 2 Cl, CHCl 2 and CCl 3 ) to give basic trinuclear chromium(III) carboxylates of the general formula [Cr 3 O(OOCR) 6 ] + Cl - . The reaction of CrCl 3 with acetic anhydride, however, gives a partially substituted product, CrCl(OOCCH 3 ) 2. The formation of basic carboxylates has been attributed to the strong affinity of Cr 3+ ions for water that they can abstract it even from pure carboxylic acids. Their addition compounds with ammonia have also been prepared. The compounds have been characterized by their elemental analyses, IR, molar conductance and magnetic measurements.

The ABX-compounds MgCuP, BaCuP(As) and BaAgP(As) have been prepared and their structures determined. MgCuP crystallizes orthorhombically in an anti-PbCl 2 -structure (space group Pnma-D 16 2h , a = 653.2(1) pm, b - 383.5(1) pm, c = 717.0(1) pm). The compounds BaCuP(As) and BaAgP(As) are isotypic and crystallize in a modified Ni 2 ln-structure (space group P6 3 /mmc-D 4 6h ) with the lattice constants: BaCuP a = 423.9(1) pm, c = 900.6(2) pm, BaCuAs a = 437.2(1) pm, c = 907.3(2) pm, BaAgP a = 449.6(1) pm, c = 882.8(2) pm, BaAgAs a = 461.3(1 )pm, c = 889.6(1) pm.

Compounds near the composition Nb 2 O 5 : WO 3 ~ 6:1 were prepared by chemical transport (at relatively low temperatures). The block structures of the obtained samples were investigated by high resolution electron microscopy. Besides unusual defects microdomains were found which still contain edgesharing blocks even at the composition 0/ΣMe = 2.53 to 2.55.

Ionisation and appearance potentials were obtained for diazene HN = NH (prepared by thermolysis of T OS N 2 H 2 M, M = Li, Na, K), isodiazene H 2 N = N (prepared by thermolysis of T OS N 2 H 2 CS and N 2 H 4 microwave radiolysis, respectively), and other hydrides N 2 H n (cf. Table I). The following energy data (kcal/mole) have been determined for diazene: heat of formation (32), enthalpy of isomerisation to isodiazene (13), NN-dissoziation energy (122), NH-dissoziation energy (81), hydrogen atom affinity (45), proton affinity (176).

Dinitrogen cobaltates [(Me 3 P) 3 CoN 2 ] 2 Mg(THF) 4 and KN 2 Co(PMe 3 ) 3 react with CoCl(PMe 3 ) 3 or NiCl 2 (PMe 3 ) 2 to give a novel binuclear complex (Me 3 P) 2 Co(CH 2 PMe 2 )(PMe 2 )Co(PMe 3 ) 2 of unusual properties. Carbon monoxide produces Me 3 P(CO) 2 Co(CH 2 PMe 2 )(PMe 2 )Co(CO) 2 PMe 3 but does not insert into the Co-C bond. A cleavage reaction by trimethylphosphite yields (Me 3 P) 2 [(MeO) 3 P] 2 CoP(O)(OMe) 2 . The molecular structure of the title compound reveals a novel heterocyclic system Co 2 P 2 C containing a CH 2 group bent out of the Co 2 P 2 plane (d(Co = Co) = 242.8(2) pm). The bond distances (d(P = C) = 171 pm, d(Co-C) = 209 pm) and angles (PCCo) = 88° suggest a type of bonding which is best described as a P-metallated phosphorane coordinated to the second Co atom via its ylide function.

By reacting RC ≡ CMgBr (R = CH 3 , C 2 H 5 , (CH 3 )Si) with perthiophosphonic anhydrides (R′PS 2 ) 2 (R′ = CH 3 , 4-CH 3 O-C 6 H 4 ) alkynyl substituted dithiophosphinic acids RC ≡ C(R′)P(S)SX (X = H) are obtained, the ammonium salts of which can be converted into the esters (X = CH 3 ) with CH 3 I. While the acids and their salts form numerous metal chelates (X = M/n), the corresponding esters give platinum(0) alkyne complexes [(PPh 3 ) 2 Pt(RCEEC(R′)P(S)SCH 3 )] on reaction with Pt(PPh 3 ) 4 .

A simple two step synthesis of the salts M[(C 5 H 5 )Co{P(0)(OC 2 H 5 ) 2 } 3 ], M = Li, Na, K, Ag, NH 4 , NMe 4 is described. The air stable, diamagnetic anion reacts as a tridentate 0,0,0-chelating ligand with all main group III elements. With sodium tetraphenylborate the cage-like cationic complex [(C 5 H 5 )Co{[P(0)(OC 2 H 5 ) 2 ] 3 BPh}] + is obtained. With M(III) = Al,Ga, In, Tithe trinuclear sandwich compounds [{(C 5 H 5 )Co[P(0)(OC 2 H 5 ) 2 ] 3 } 2 M] + are formed, which contain MO 6 octahedra. With M(III) = TI a coupling constant 6 J(T10P0CCH) = 1.0 Hz is observed.

Ternary copper(II) complexes containing the dianion of 3-n-nonylcatechol and a number of bidentate nitrogen containing counter ligands have been prepared and characterized. It has been demonstrated that, in the presence of oxygen, the catecholato ligand undergoes intradiol ring cleavage in a fashion similar to that carried out by intradiol aromatic dioxygenases. The 3-n-nonylcatecholato ligand was chosen as an analog for the naturally occuring 3-pentadecylcatechols or "urushiols" which are the active allergens in plants such as poison ivy.

Synthesis of the silicon analogue VI b of the drug pridinol and of its homologue VI a was achieved via eq. (l-5b) (Scheme 1). The novel compounds IVa-VIb are described in their properties and confirmed in their structures (Tables I-IV). Some preliminary pharma-cological investigations suggest spasmolytical effects of sila-pridinol seeming to be somewhat better than those of pridinol itself.

The thioamidato complexes C 5 H 5 (CO) 2 MoSC(R)NCH(CH 3 ) (Ar), derived from acetic acid R = CH 3 and benzoic acid R = C 6 H 5 , were prepared and characterized. The diastereo-isomers, differing in their 1 H NMR spectra, were partly separated by fractional crystallization. After equilibration with respect to the labile Mo configuration the diastereoisomer ratio, a measure for the asymmetric induction from the chiral ligand on the formation of the two Mo configurations at equilibrium, was determined by 1 H NMR integration. The asymmetric induction is very high for Ar = o-tolyl [76% (R = C 6 H 3 ) and 84% (R = C 6 H 5 )] compared to Ar = phenyl [48% (R = CH 3 ) and 56% (R = C 6 H 5 )] and Ar = m-and p-tolyl [52 and 44% (R = CH 3 )]. The (CO) 3 Cr complexed phenyl substituent with only 10% asymmetric induction does not show the β-phenyl effect, a weak attraction between aryl groups in β-position to the metal atom and the MC 5 H 5 moiety.

Reaction of N,N-dialkyl-β-aminoketones (5 and 7) with hydroxylamine hydrochloride in pyridine results in the dealkylated oximine (6). The mechanism of this N-dealkylation may be explained as due to the neighbouring group participation of the oximine formed during the reaction.

Several ester and amide derivatives of 3-(1-methyl-5-nitro-2-benzimidazolyl)acrylic acid have been prepared for testing as potential antischistosomal agents. The starting acid was conveniently synthesized from the corresponding aldehyde derivative through the Knövenagel-Döbner reaction. The utility of EEDQ as a coupler for the synthesis of peptides has been successfully extended to the coupling of N-heterocyclic acrylic acid derivatives and various amines.

The photochemical behaviour of amidopyrine (1) in cyclohexane was studied. The photodimer (2) and three fragmentation products (3-5) could be isolated and identified with the help of spectroscopic methods. The participation of 4-pyrazolin-3-ones in photochemical cycloadditions is demonstrated for the first time.

We describe the preparation of unsubstituted 1 a, of 4-methoxy- (1b), and of 5-methoxynaphtho[1,2-d]-1,3-dioxole (1 c). Treatment of 1 a with bromine leads to 5-bromo-naphtho- [1,2-d]-1,3-dioxole (1d). The carboxylic acid 1f and 5-methyl-thio-naphtho[1,2-d]-1,3- dioxole (lg) are prepared by bromine-lithium-exchange from ld. Formylation yielding 1i and bromination yielding 1h show that 4-methoxy-naphtho[1,2-d]-1,3-dioxole can easily undergo electrophilic substitution. Because of less Ss-reactivity of 1c the carboxylic acid 1l and methyl-thio-naphtho[l,2-d]- 1,3-dioxole (In) can only be prepared from the lithium-compound as intermediate. Naphtho[2,3-d]-1,3-dioxole (2a) can easily undergo electrophilic substitution, showed by nitration yielding 2b, acetylation yielding 2c, bromination yielding 2d and 2e. The carboxylic acid 2j, the methyl-derivative 2k, the thionaphthole 2l, and the aldehyde 2m are prepared from the lithium-compound of 2d. Treating 2e with n-butyl-lithium leads to the dilithium-naphthyl derivative, a suitable starting material to obtain the dimethyl-compound 2n, the dicarboxylic acid 2o, and the dialdehyde 2p. Monomethyl-thio- 2q) and dimethyl-thio-naphtho[2,3-d]-1,3-dioxole (2r) are prepared in the same manner.

Photo-reactions initiated by triplet sensitized excitation of 1,2,3,5-exo-6-pentamethyl- 4-methylene-bicyclo[3.1.0]hex-2-ene (exo-1) and 1,2,3,5-endo-6-pentamethyl-4-methylenebicyclo[3.1.0]hex-2-ene (endo-1) are studied qualitatively and quantitatively. It is demonstrated, that - in contrast to the molecular rearrangement to 1,2,3,4,6-pentamethyl- 5-methylene-cyclohexa-1,3-diene following singlet excitation - under triplet excitation exclusively reversible erro-endo-isomerization occurs.

Methylation of etiobiliverdin-IV-γ yields a ring-A N-methylated product the structure of which was proven by comparison with the corresponding monolactimether and the ring-B methylated product which was synthesized on an independent route. The configura-tion (Z,Z,Z) was deduced by 1 H-NMR experiments and a more or less helical conformation which is most twisted at the ring-A methine fragment was found. Photoisomerization exclusively takes place at this position giving the (E,Z,Z) diastereomer, a reaction which is discussed in terms of the correlation of light absorption, methine single bond twist and photochemical selectivity.

The 121 Sb Mössbauer spectra of the mixed valence compounds (RH + ) 8 (Cl - ) 4 SbCl 6 3- SbCl 6 - with R equal CH 3 CH(NH 2 )CH 3 (1), CH 3 CH(NH 2 )CH 2 CH 3 (2) are reported and the results are discussed.

A new tin-cobaltcarbonyl-cluster, a homo-logue of the methylidyne clusters, has been prepared and identified by IR and masspectro-metric measurements.

The synthesis of the N-organomercury nucleosides C 6 H 5 HgL (LH = guanosine, inosine, thymidine, uridine) is described.

N-Cyano-sulfurdifluoride-imide NC-NSF2 and N-cyano-sulfuroxide-difluoride-imide NC-NSOF 2 will react with AsFs to give the N-bonded nitrile adducts F 5 As · NC-NSF 2 (F 5 As · NC-NSOF 2 ). With [M(CO) 5 SO 2 ]+AsF 6 - (M=Mn,Re) the expected complexes [(CO) 5 MNC-NSF 2 ]+AsF 6 - [(CO) 5 MNC-NSF 2 ]+AsF 6 -are formed in quantitative yield.

119 Sn-NMR spectra of a 1:1 mixture of [(CH 3 ) 2 SnS] 3 (1) and [(CH 3 ) 2 SnNC 2 H 5 ] 3 (2) were recorded to demonstrate the utility of 119 Sn-FT-NMR in exchange reactions.

The anticancer active compound, cis-dichloro-diammine platinum (II), and the biomolecules cytosine and thymine form paramagnetic complexes in aqueous solution. The electron spin resonance spectra which can be attributed to paramagnetic platinum, exhibit large anisotropy in frozen solution as well as in liquid solution. This fact can be explained by assuming poly-meric structures also in liquid solution.

The X-ray photoelectron spectra of cobalt(III) complexes in an unusual spin triplet state are reported. The binding energies in the 2P spectral region are somewhat low and the spectra exhibit rather strong satellite structure. The Co 2P 1/2 -CO 2P 3/2 separations and satellite intensities appear to be related to the magnetic moments of the complexes as has been suggested previously for cobalt(II) compounds.

It is demonstrated that the Wiesner reaction (detection of lignin with phloroglucinol/HCl) is due not only to cinnamic aldehyde but also to cinnamic alcohol units of the lignin. The limits of detection of some compounds related to lignin with phloroglucinol/HCl, naphthoresor-cinol/HCl and orcinol/HCl are determined. The chemistry of the reactions is discussed.

In früheren Publikationen hatten wir berichtet, daß quartäre Pyridinium-Salze Carboxamide unter